<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			function foo1(x){
				console.log(arguments);
				return x;
			}
			foo(1, 2, 3, 4, 5);
			
			function foo2(x){
				console.log(arguments);
				return x;
			}(1, 2, 3, 4, 5); 	//js引擎认为()里的是个表达式所以不报错
			
			(function foo3(x){
				console.log(arguments);
				return x;
			})(1, 2, 3, 4, 5);
		</script>
	</body>
</html>
